This application pertains to the art of thermal torches and more particularly to consumable thermal lanches or torches.
The invention is particularly applicable to an oxygen lance of the type typically employed for boring, cutting, burning and the like of hard base materials and will be described with particular reference thereto; however, it will be appreciated by those skilled in the art that the invention has broader applications and may be adapted to use in other environments and applications.
The oxygen lance and oxygen lance process represent one of the oldest commercial uses of oxygen for piercing and cutting holes in hard base materials including practically all ferrous metals and many other materials such as concrete, slag, rock and the like. Initially, such lances simply comprised an elongated length of black iron pipe connected at one end to an oxygen hose, regulator and cylinder or manifold so that only oxygen flowed through the lance pipe. In operation, and in order to initiate the thermic reaction of the lance, an area on the material to be treated is preheated to kindling temperature. The end of the lance is then brought against the heated area and the supply of oxygen then turned on. This then oxydizes the material to be treated with sufficient heat being produced to continue the cut or hole with oxygen alone without any additional heat or flame required to facilitate progress. The discharge end of the lance is held in the cut or hole so that the cutting oxygen stream emerges at the point of cutting or oxidation. This heats and burns the end of the pipe so that as the operation proceeds, the lance is consumed and must be replaced from time to time with a new length of iron pipe. Only a small portion of the oxygen consumed is required by the oxidation of the lance itself but the heat of the burning lance assists the cutting. Once started, the reaction is very vigorous so that a lot of "splatter" outwardly from and at the discharge end of the lance is normally associated with this process.
Until fairly recently, practically no development work had been done in the area of improving the basic oxygen lance constructions and cutting techniques as they remained substantially the same as when first developed. However, it had been previously noted that the cutting action could be increased by using a lance pipe having greater wall thickness or by inserting one or more steel rods into the pipe. The thicker pipe and rod inserts furnish both additional fuel and heat and the rods decrease the area of effective opening in the lance pipe so that the oxygen stream gains greater velocity as it travels through the lance. Thus, the erroding effect on the material being treated is increased. Such increase, in turn, increases the "splatter" problem as well as flame spreading so that the cutting action is not as concentrated as desired in order to realize the ultimate in cutting action.
Over the last 10 years or so, there have been renewed interests in oxygen lance techniques resulting in many purported improvements on and to the basic oxygen lance structure. Most of these improvements are directed to the areas of the manner of disposing one or more elongated rods within the outer lance casing, the mounting of the various component parts relative to each other, particular and specialized configurations for the outer casing and inner rods and particular cooperative relationships between the inner rods when received within the outer casing. Typical of such fairly recent patents are U.S. Pat. Nos. 3,260,076; 3,460,223; 3,487,791; 3,500,774; 3,507,230; 3,507,231; 3,570,419; 3,602,620; 3,738,288; and, 3,921,542. However, none of the various improvements, as exemplified by these various patents, focus upon or provide any solution for reducing the "splattering" problem or for reducing flame spreading to intensify the overall thermic reaction.
The present invention contemplates new and improved apparatus and method which overcome the above referred to problems and others and provides a new and improved thermal torch or lance and method which is fairly simple in design, simple to manufacture, economical to use, confines and intensifies the thermic reaction and which is readily adapted to use in a plurality of boring, cutting, burning and the like operations of hard base materials in different environments.